A gunman sexually assaulted at least one woman, then fatally shot her inside a Catholic gift shop, police in St. Louis said.

The apparently random attack took place Monday afternoon, and by night, the gunman remained at large. Police said they had not identified the man, and it did not appear as if he knew anyone inside the store.

He was described as a white man, 45 to 50 years old, 5 feet 7 inches tall, with a heavyset build. He was wearing a black jacket, blue jeans, and a black or gray hat, and it wasn't known if he had fled on foot or in a vehicle, St. Louis County Police Sgt. Shawn McGuire said.

"We're still scouring the area for surveillance cameras," he told reporters. "We're still waiting for calls from the public."

Police first received a 911 call around 3:20 p.m. that there had been a shooting at Catholic Supply, a gift and church supplies store in a suburban shopping center outside St. Louis. The gunman entered the store and ordered women inside to take their clothes off, the 911 caller told police, according to the St. Louis Post-Dispatch.

When officers arrived, they confirmed one woman had been shot and sexually assaulted. It wasn't immediately clear if other women in the store were also sexually assaulted.

The woman was taken to a hospital with critical injuries and died Monday night, police said. Her name was not immediately released, although KMOV reported that she was 53 years old.

In a tweet, Catholic Supply asked for prayers for everyone involved. The Archdiocese of St. Louis also called for prayers.

"Our hearts go out to the victims of this horrific tragedy at Catholic Supply," Archbishop Robert Carlson said in a statement. "We join with civil authorities asking for the community's assistance in apprehending the culprit of this crime."

In a statement sent to BuzzFeed News, Catholic Supply president Dan Stutte called the attack a "senseless tragedy."

"The safety and security of our employees and customers is our highest priority. Our retail locations will be closed for business on Tuesday and will reopen on Wednesday."

He also asked people to join them in prayer for the "victims and their families."

Claudia Koerner is a reporter for BuzzFeed News and is based in Los Angeles.